The population of vaquitas is now very small, since there are only between 6 and 19, according to the services of the United States Trade Representative (USTR).
This animal lives in the warm waters of the northern Gulf of California and the Sea of Cortez in Mexico.
The USTR criticizes Mexico for not preventing the use of illegal fishing nets to catch shrimp and totoaba fish, which turns out to be the number one cause of death for vaquitas.
"Scientists maintain that the species continues to be biologically viable provided it is given enough space to recover," the USTR said in a statement.
The US administration invoked environmental provisions of the US-Mexico-Canada (EUMC) trade treaty to launch consultations with Mexico City.
This is the first time that one of the three signatory countries has invoked the environmental provisions of the free trade treaty which entered into force in July 2020.
The consultations also focus on the illegal fishing of totoaba fish.
A USTR official told reporters that he had "serious concerns about Mexico's enforcement of environmental regulations."
Under the EUMC Treaty, consultations must be scheduled within 30 days.
Moreover, at least 75 days must pass before Washington can escalate this dispute.
The Mexican Ministry of the Economy indicated for its part that it would coordinate the work of the authorities of the two countries in order to highlight "the efforts and the measures adopted to protect marine species" in Mexican waters.
"The Mexican government reaffirms its commitment to the execution of the trade treaty (EUMC) and the responsibilities it entails," he added in a statement.
If no agreement was reached, customs duties could be imposed.
But senior USTR officials warned it was "premature" to discuss any punitive action.
© 2022 AFP